title: Elucidating internucleosome interactions and the roles of histone tails.
abstract: The nucleosome is the first level of genome organization and regulation in eukaryotes where negatively charged DNA is wrapped around largely positively charged histone proteins. Interaction between nucleosomes is dominated by electrostatics at long range and guided by specific contacts at short range, particularly involving their flexible histone tails. We have thus quantified how internucleosome interactions are modulated by salts (KCl, MgCl2) and histone tail deletions (H3, H4 N-terminal), using small-angle x-ray scattering and theoretical modeling. We found that measured effective charges at low salts are ∼1/5th of the theoretically predicted renormalized charges and that H4 tail deletion suppresses the attraction at high salts to a larger extent than H3 tail deletion.
authors.affiliation: Department of Physics, George Washington University, Washington, DC, USA.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Howell
authors.forename: Kurt
authors.initials: K
authors.lastname: Andresen
authors.forename: Isabel
authors.initials: I
authors.lastname: Jimenez-Useche
authors.forename: Chongli
authors.initials: C
authors.lastname: Yuan
authors.forename: Xiangyun
authors.initials: X
authors.lastname: Qiu
mesh_terms: D000818:Animals; D002645:Chickens; D006657:Histones / Q000737:chemistry* / Q000378:metabolism*; D015636:Magnesium Chloride / Q000494:pharmacology; D009707:Nucleosomes / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D053838:Scattering, Small Angle; D055672:Static Electricity; D014961:X-Ray Diffraction
chemical_list: D006657:Histones; D009707:Nucleosomes; D015636:Magnesium Chloride; D011189:Potassium Chloride